The “Letting down” is a reflex, which is stimulated by the hormone oxytocin. The actual milking can begin after the letting down reflex has been elicited. The hormone oxytocin is required to enable milch animal to fully letting down the bulk of her milk. A sucking calf or a gentle pre-milking routine is the only way for the ilch animal to release this hormone and letting down her milk more fully.
Suckling for a short period (1-2 minutes only) before milking, to stimulate milk letting down is a common practice in many farms, but the presence of calves during milking may complicate management, specially when machine milking is used. An alternatively used in some farms is only to allow suckling after milking.
Milking stimuli, such as a sucking calf, a warm wash cloth, the regime of parlour etc., causes the release of a hormone called oxytocin. Oxytocin is released from the pituitary gland, below the brain, to begin the process of milk letting down. As a result of this hormone stimulation, the muscles begin to compress the alveoli, causing a pressure in the udder known as letting down reflex, and the milk components stored in the lumen are released into the duct system. The milk is forced down into the teat cistern from which it is milked. The letting down reflex fades as the oxytocin is degraded, within 4-7 minutes. It is very difficult to milk after this time.
Ejection of milk is accomplished by contraction of the myo-epithelial cells surrounding each alveolus. The ejection process results in a rapid transfer of milk from the lobulo-alveolar spaces into larger ducts. The flow of milk due to passive withdrawal, which is greatly increased following ejection, is commonly known as letting down. In some occasions, the intra-mammary pressure is sufficiently great to overcome the resistance of the teat sphincter so that the milk may leak from the teat. Milk ejection is a neurohormonal reflex associated with the release of oxytocin. Milk ejection reflex has a neural (afferent) and a hormonal (efferent) component.
Physical stimulation of the teats, either by the calf's suckling or the milkers hands, excite receptors from which nerve impulses are send to the posterior pituitary gland causing secretion of the hormone oxytocin. The hormone is transported via the blood to the mammary gland. Because both hormones and nerve impulses are involved in the milk ejection reflex, it is called a neurohormonal reflex. Oxytocin stimulates the contraction of the alveoli and small ducts thereby emptying the milk into the larger ducts and the cistern. Hereafter the milk can be evacuated from the udder.
The contraction of the alveoli may, to some extent, be enhanced by tactile stimuli of the udder (massaging, squeezing) the so-called tap reflex. When calves suckle, they butt at the udder in order to increase milk secretion. Manual massage of the udder during milking imitates this reflex.
The greatest amount of innervation in the mammary gland of the milch animal is in the teats. Mechanical stimulation of the teat activates pressure-sensitive nerve receptors in the skin of the teat. The nerve impulses travel to the brain through the spinothalamic nerve tract. When the cell bodies of the oxytocin-containing neurons are stimulated by these impulses originating in the teat, an action potential moves down the oxytocin-containing neurons from the cell body in the hypothalamus down the axon to the neuron ending in the posterior pituitary. This causes release of oxytocin and neurophysin into the blood. The efferent pathway starts at this point. The efferent pathway begins with the release of oxytocin into the blood. Oxytocin is released into the blood in response to action potential of nerve impulses originated in the teat. It then travels to the mammary gland and binds to protein receptor sites on the epithelial secretory cells. This results in contraction of the secretory cells and expulsion of milk from the mammary gland.
Various stressful stimuli that inhibit milk ejection are associated with increased activity of the sympathetic nervous system. Oxytocin action can be blocked by catecholamines (epinephrine and norepinephrine). The hormones are usually released in response to stressful situations and increase the tone of the smooth muscles of the mammary ducts and blood vessels. This results in the reduction of oxytocin reaching the myo-epithelial cells and partial occlusion of the mammary ducts. Moreover, epinepherin directly blocks oxytocin from binding to myo-epithelial cells. This is termed as peripheral inhibition of milk ejection. Thus, exogenous oxytocin will not cause milk ejection in animals exhibiting peripheral inhibition.
A common cause of failure to milk ejection is associated with stress. The stress inhibits the release of oxytocin from the posterior pituitary gland (central inhibition of milk ejection). Exogenous oxytocin is usually administered in these cases causing milk ejection. Based on the above discussion about peripheral and central inhibition of milk ejection, it can be stated that milk ejection occurs as a result of oxytocin release, which is normally couples with inhibition of the central and peripheral inhibitory controls. Milch animals are sensitive to changes in the environment. They may withhold the milk, if they are uncomfortable with the situation. If the animals are stressed, scared or in pain, the hormone adrenaline is secreted. This hormone causes constriction of the blood vessels, thereby hindering the supply of sufficient amount of oxytocin to the udder. Adrenaline also directly acts on the myo-epithelial cells in the alveoli by blocking the oxytocin receptors. The inhibition if milk letting down will result in the leaving of milk in the secretory parts of the udder. Continuous exposure of stress to the cattle will affect the milk production negatively. Post parturient death of calf, separation of calf after birth, change of place, owner, climatic conditions and stress due to long travel, change of milker or milking routine, application of wrong milking technique or milking machines in bad conditions are the main reasons for the milch animals to withhold the milk.
In the case of cattle which do not normally letting down milk in the absence of the calf, it is traditional practice to stimulate milk flow by very brief suckling followed by partial milking, after which the calf is allowed to suck the residual milk. Poor milk ejection can be due to impaired oxytocin release, mammary insensitivity to oxytocin or to pituitary dysfunction (Murugaiyah et al., 2001). Moreover, cow's temperament can contribute to the impaired milk ejection since stress was found to inhibit oxytocin release (Bruckmaier and Blum, 1998).
Milch animals are susceptible to shock or stress caused from nutritional deficiencies, trauma, infection or extreme environmental changes such as lot adaptation stress in animal. While such stress does not necessarily exhibit its most extreme form in shock in all cases, it nevertheless adversely affects the milch animal. Unfortunately, if animals are frightened, fear may trigger the release of the hormone adrenaline, which is an antagonist of oxytocin. Death of calves is a common reason for short lactations, as tropical milch animal often fail to letting down of milk unless stimulated by suckling. Due to this there is a decrease in the milk production.
The milk producers are not having alternative remedy for solving problem of letting down of milk in milch animals, oxytocin injection is still used for the same inspite of knowing its undesirable side effects. Moreover the biochemical half-life of injected oxytocin is very short and requires several injections. Oxytocin injection which may result into get animal habituate as well as hormonal imbalance which causes fertility problems like repeat breeding, threats of abortion and threats of uterine prolapse. Biosecurity is another problem, since many farmers use same needle for the different animals which spreads contagious diseases. A better way would be the use of a long action composition, which provided a similar response over an extended time period.
There are very few patents available for solving the problem of milk letting down in cattle and related one include U.S. Pat. No. 4,490,391, which discloses the composition for treatment of shock and stress in animals comprising equal volume amounts of solutions of sodium acetate and sodium propionate. U.S. Pat. No. 4,349,544 discloses the method for increasing the milk let down in mammals by the use of long-acting oxytocin analogs. But none of the prior art documents disclose the solving problem of letting down of milk in milch animals by using the naturally available medicinal herbs.
A significant problem with herbal medicine is that herbs are slow acting in treating an ailment. In contrast, allopathic drugs act comparatively quickly. For this reason, veterinarians prefer allopathic drugs as the effective means of treatment, even though the drugs have side effects. Clearly, it would be desirable to increase the speed by which herbal medicines act, but while maintaining the natural, herbal character of the medicine so as to avoid or minimize harmful side effects. An increasing number of people are gaining awareness of the advantages of herbal medicine together with a concern over the disadvantages of modern purified drugs. Consequently, there has been an increasing public interest in the use of herbal based compositions. Thus, many people consider herbs primarily useful as a maintenance or prophylactic treatment to be taken regularly in order to prevent onset of illness. A faster acting type of herbal medicine would create far broader utility.
Accordingly, there is a real and continuing need for an inexpensive shock and/or stress treatment composition to cattle for increasing the milk production. Hence the present inventor aims to develop the compositions and specifically to those compositions with naturally occurring herb extracts and/or bioactive fraction or powder to solve the problem of letting down of milk in milch animals without the undesired side effects. In particular, the herbal compositions, which can be fed to cattle for solving the problems letting down of milk in milch animal. The present invention provides compositions that require little technical expertise to use and may be used as a nutritional supplement for milch animal. The compositions are inexpensive and cost effective.